>HAVE GUMSHOE, WILL TRAVEL THREE TV DETECTIVES FIND OUT-OF-town adventure this week. In Spenser: The Judas Goat (Lifetime, Thurs., Dec. 1, 9 p.m. ET), Robert Urich, as the Boston P.I., ventures to Ottawa to foil an assassin, getting help from Hawk (Avery Brooks). At the same time, PBS's Mystery! launches four new Hercule Poirot puzzles beginning with "The Chocolate Box." David Suchet again stars as the dapper deducer who returns to Belgium to resolve a 20-year-old case. On A&E, Imogen Stubbs is back in Anna Lee: Stalker (Tues., Dec. 6, 9 p.m. ET). A missing person leads Anna away from London into trouble in the woods of Somerset.